Effects of concentrate‐to‐forage ratios and 2‐methylbutyrate supplementation on ruminal fermentation,bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers          下载免费PDF全文

C. Wang  Q. Liu  G. Guo  W. J. Huo  C. X. Pei  S. L. Zhang  H. Wang 《Journal of animal physiology and animal nutrition》2018,102(4):901-909

This study evaluated the effects of dietary concentrate levels and 2‐methylbutyrate (2MB ) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate‐concentrate (400 g/kg diet [MC ]) or high‐concentrate (600 g/kg diet [HC ]) diets were fed with or without 2MB (0 g/day [2MB ?] or 15.0 g/day [2MB +]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate‐to‐propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH ₃‐N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus , Ruminococcus flavefaciens , Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α‐amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.  相似文献   

Amino acid profiles of rumen undegradable protein: a comparison between forages including cereal straws and alfalfa and their respective total mixed rations          下载免费PDF全文

B. Wang  L. S. Jiang  J. X. Liu 《Journal of animal physiology and animal nutrition》2018,102(3):601-610

Optimizing the amino acid (AA) profile of rumen undegradable protein (RUP) can positively affect the amount of milk protein. This study was conducted to improve knowledge regarding the AA profile of rumen undegradable protein from corn stover, rice straw and alfalfa hay as well as the total mixed ratio diets (TMR) based on one of them as forage source [forage‐to‐concentrate ratio of 45:55 (30% of corn stover (CS), 30% of rice straw (RS), 23% of alfalfa hay (AH) and dry matter basis)]. The other ingredients in the three TMR diets were similar. The RUP of all the forages and diets was estimated by incubation for 16 hr in the rumen of three ruminally cannulated lactating cows. All residues were corrected for microbial colonization, which was necessary in determining the AA composition of RUP from feed samples using in situ method. Compared with their original AA composition, the AA pattern of forages and forage‐based diets changed drastically after rumen exposure. In addition, the extent of ruminal degradation of analysed AA was not constant among the forages. The greatest individual AA degradability of alfalfa hay and corn stover was Pro, but was His of rice straw. A remarkable difference was observed between microbial attachment corrected and uncorrected AA profiles of RUP, except for alfalfa hay and His in the three forages and TMR diets. The ruminal AA degradability of cereal straws was altered compared with alfalfa hay but not for the TMR diets. In summary, the AA composition of forages and TMR‐based diets changed significantly after ruminal exposure, indicating that the original AA profiles of the feed cannot represent its AA composition of RUP. The AA profile of RUP and ruminal AA degradability for corn stover and rice straw contributed to missing information in the field.  相似文献   

浅议岩土工程勘察中的野外钻探     

彭国萍 《林业科技情报》2013,45(3):124-125

野外钻探是岩土工程勘察的基础和技术依据，其质量的好坏直接影响到报告的准确性。但在实际操作过程中，野外钻探存在许多问题，应该引起从业人员的足够重视。本文主要介绍野外钻探的任务和内容，并简要分析操作过程中存在的问题。  相似文献   

Sex Determination of Bovine Embryo Biopsies Using in situ Hybridization*     

P.D. Thomsen  M. Schwerin  P.H. Poulsen  B. Avery 《Reproduction in domestic animals》1991,26(2):66-69

A male specific bovine DNA fragment was used as probe to determine the sex of bovine interphase cells by in situ hybridization. This method also proved useful for determining the sex of bovine embryos.  相似文献   

Detection of papillomavirus-DNA in mesenchymal tumour cells and not in the hyperplastic epithelium of feline sarcoids     

Teifke JP  Kidney BA  Löhr CV  Yager JA 《Veterinary dermatology》2003,14(1):47-56

Abstract We examined 12 formalin-fixed paraffin-embedded feline skin tumours which had the histopathological features of fibropapillomas for the presence of papillomavirus (PV) DNA using touchdown polymerase chain recation (PCR), DNA sequencing and nonradioactive in situ hybridization. Nine of the tumours contained a 102-bp PCR product demonstrated using consensus PV primers that amplify a portion of the L1 gene. The nucleotide sequences are closely related, but not identical to that of ovine PV type 2, rabbit oral PV and reindeer PV. The deduced amino acid sequences had strong homologies with the major capsid protein L1 of deer PV, bovine papillomavirus (BPV) 1 and BPV 2, and European elk PV. Although PV antigens were not detected in any of the tumours by immunohistochemistry, PV DNA was demonstrated in individual mesenchymal cells or cell nests of 4/12 tumours by in situ hybridization. A nonproductive infection of mesenchymal fibroblast-like tumour cells with a papillomavirus would explain the lack of PV antigen expression and the absence of PV DNA in the hyperplastic epithelium. Because these tumours and their pathogenesis are similar to equine sarcoids, we suggest that they should be reclassified as 'feline sarcoids' instead of fibropapillomas.  相似文献   

一个山羊Ⅰ型毛角蛋白基因的序列及其在皮肤中的表达   总被引：7，自引：0，他引：7  

尹俊  李金泉  张燕军  李长青  赖双英  张文广  高爱琴  菊林花 《畜牧兽医学报》2006,37(1):18-22

角蛋白家族包含表皮软角蛋白和毛发硬角蛋白，可以分为酸性Ⅰ型和碱性或中性的Ⅱ型角蛋白亚家族。从构建的成年山羊皮肤cDNA文库和ESTs分析中发现了和与绵羊羊毛角蛋白8C1和人Ⅰ型毛发角蛋白相应cDNA序列高度同源的序列，经序列分析证明是一个山羊毛发特异性角蛋白，命名为山羊Ⅰ型毛角蛋白1（gHa1），Gen Bank序列号为AY510110．1。推导的读码框ORF由413氨基酸组成，与绵羊8C1角蛋白的序列一致性为97．8％。原位杂交显示它在皮肤初级和次级毛囊的皮质层有强烈的表达。  相似文献   

成年发情期奶山羊下丘脑催产素及其mRNA的表达     

陈树林周建平  李文献张艳李耀辉  毛海鹏蒲强红 《中国兽医科技》2007,37(5):435-439

应用免疫组织化学SP法和原位杂交法研究了催产素（oxytocin，OT）及OT mRNA在成年发情期奶山羊下丘脑中的分布和表达。结果，OT免疫反应阳性细胞主要分布在视上核和室旁核，在视上弥散核、弓状核、室周核和乳头体各核团也存在免疫阳性神经元；在室旁核、视上弥散核、正中隆起和第三脑室附近有较多数量的强阳性神经纤维，在交叉上核有少量阳性神经纤维。在下丘脑23个核团（区）中均能检测出OT mRNA的阳性细胞。结果表明，OT和OT mRNA在下丘脑中分布广泛，且OT可能通过轴突传递和血液运输，将OT mRNA合成的OT运送到别的核团；OT在奶山羊发情过程中发挥了重要作用。  相似文献   

中国半湿润、半干旱、干旱地区某些土壤的氧化还原状况   总被引：2，自引：0，他引：2  

丁昌璞  李九玉 《干旱区研究》2006,23(4):515-520

用新的电化学方法原位考察了褐土、灰钙土、棕漠土、黑土、风沙土、灌淤土、盐土、碱土、亚高山草甸土、灰褐土、水稻土和旱地土壤的氧化还原状况.综合已有原位测定结果,地带性土壤的电位(Eh)由南向北的空间分异与其水平地带谱相应;亚高山草甸土和灰褐土的氧化还原状况随山体高度和植物群落而呈垂直分异趋势.比较了自然土壤、旱作土壤和水稻土的电位(Eh)差异和特征,水稻土中的氧化还原过程远较自然土壤和旱作土壤中者为甚,其强度和速度不逊于南方地区水稻土.新的电化学方法的原位测定贴近于自然.  相似文献   

梨组织中苹果褪绿叶斑病毒的原位RT-PCR检测   总被引：6，自引：2，他引：6  

牛建新  周民生  马兵钢  赵英  刘宏 《园艺学报》2007,34(1):53-57

 为了建立梨树苹果褪绿叶斑病毒原位RT-PCR检测技术, 用已知带有苹果褪绿叶斑病毒的库尔勒香梨和无病毒实生苗叶片为材料, 利用D IG标记, 研究了香梨病毒的叶片石蜡切片IS-RT-PCR检测技术。包括AMV逆转录酶、dNTPs、RNasin及互补引物浓度对cDNA合成的影响, 退火温度、Taq DNA聚合酶、Mg²⁺ 、引物浓度及循环次数对原位PCR效果的影响。结果表明: RNasin的用量大于0.2 U·μL^-1时,信号强度随着RNasin量的加大而增强; 只有当dNTPs浓度达1.0 mmol·L^-1时才能生成一定量的cDNA;AMV浓度在0.3～0.5 U·μL^-1均可进行正常的逆转录, 而且在该范围内产物的量随AMV浓度提高而增多; 引物浓度达到0.9μmol·L^-1以上时才能进行有效的逆转录, 并且生成的cDNA的量随引物浓度增大而增加。原位扩增ACLSV的cDNA适合退火温度为56℃。循环20～30次可出现较强的蓝色信号, 引物浓度在0.8～1.2μmol·L^-1时显色较好; Taq酶浓度为20 U·mL^-1以上, 均显示较深的蓝色; Mg^{2 +}浓度为1.5mmol·L^-1就可满足原位PCR所需。获得了苹果褪绿叶斑病毒的原位PCR优化检测体系, 利用建立的优化程序对香梨样品进行了检测验证, 取得了很好效果。  相似文献   

海南坡鹿迁地保护现状与建议     

卢学理  袁喜才  李善元  张海 《野生动物》2007,28(2):43-45

迁地保护的海南坡鹿种群可以分为野放、半野放和圈养等3种主要类型。野放种群个体数量最多，约占迁地保护种群个体总数的55．3％；其次为半野放种群，其个体数量占35．6％；圈养种群个体数量最少，只占9．1％。半野放是一种较为稳妥的坡鹿种群恢复方式。在海南坡鹿的迁地保护中，应该增加半野放种群个体数量。本文就海南坡鹿的迁地保护提出了7点保护管理及科学研究建议。  相似文献